Telecommunication system



4 Sheets-Sheet 1 G. DEAKIN TELECOMMUNICATION- SYSTEM Filed June 2l, 1943L S man May 22, 1945.

May 22, 1945. G. DEAKIN y 2,376,346

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TRUNK FINDERS n A CORD' CT.. OUT TRUNK JACK G. DEAKIN 2,376,346

TELECOMMUNICATION SYSTEM v Filed June 21, 1943 4 Sheets-Sheet 4 SMNBl..LnO

f r fr n: 6 4g 0 0 a l e S 1 s t *1L *L *L *L *L El R Patented May 2,2,1945 2,316,346 'rEmcoMMUNIoA'rroN SYSTEM Gerald Deakin, ternational NewYork, N. Y.,

New York, N. Y., Standard Electric Corporation,

a corporation ot Delaware assignor to In- Appllcation June 21, 1943,Serial No. 491,628

Claims.

This invention relates to new and useful improvements in selectingarrangements for telecommunication systems and particularly toarrangements adapted for controlling successive `se lectlng stages inautomatic telephone exchange systems.

According to the present invention, a selecting arrangement is providedin which a broad band or potentials is provided to determine a firstselecting stage. This broad band includes a plurality of narrow bands ofpotentials determinative of a second selecting stage. A plurality offirst finder switches, e. g., are arranged to operate on any of thenarrow bands, i. e., on the full width of the broad band to perform thefirst-selection. Then second switches, e. g., a group of finders operatein accordance with the specific narrow band of potentials applied. Forinstance, the potentials selected by a first finder is extended to thebanks of a plurality of second finders, each of which is arranged toselect only one tentials.

The selecting arrangement will flndmany applications totelecommunication systems. When applied to arrangements for identifyingthe designations of calling lines, a single identifying equipmentprovided in an exchange may be used simultaneously to identify aplurality of calling lines, as distinguished from prior selectingarrangements which permitted the identification of only one line at atime. l

The invention will now -be described in greater detail as applied to atelephone exchange system of the general type described in my co-pendingapplication, Serial No. 484,184, filed April 23, 1943, and theapplication of H. F. Herbig, Serial No. 485,827, filed May 6, 1943, nowPatent No. 2,354,682, issued August l, 1944.

In the drawings which illustrate only as much of the system as isnecessary for a clear understanding ofthe invention 1 illustrates thegeneral selecting scheme;

Fig. 2, the test circuit of one of the identification findersillustrated in Fig. 1;

Fig. 3, some uses of the identification arrange-l ment illustrated inFigs. 1 and 2; and

Fig. 4, the application of the identification arrangement toout-trunking.

Referring now to Fig. 1, only the test terminals and test brushes areshown of switches used in the establishment of an automatic telephoneconnection of the type `illustrated in my said co'- pending'application.A calling line may .beconnected with a called line over a first linefinder. an A link, a second line finder, a B link and then over first,second, third, fourth, penultimate and iinal group selectors. However,in the present narrow band of p0- arrangement, no identification relayis provided in each A link, the t brush,oify each iirst line finderbeing connectedr direct to a terminal of a second 1, I have shown twogroups arrangement andv line nnder. Each t wire of an A link in the samegroup of one hundred lines, is connected through a positively polarizedrectifier S+ and a resistance R. to a common starting relay Gsr. In Fig.

of rst line finders, group #l serving lines |00 to |99 and group 4#t5serving lines 500 to 599.

A plurality of groups of first identication finders is provided, eachgroup having terminal banks which are multipled to the corresponding Tterminals in the banks of the rst line iinders. One first identificationiinder is provided per one hundred subscribers lines. Theseidentification finders, just as the line finders and group selectorshave, of course, the other customary terminals and cooperating brushes.

The t brushes of the iirst identification finders are connected to theterminal banks of second identification finders per identificationcircuit. A test circuit like the brush of each second identificationnder. The t wires of the six second identification finders are shown asconnected to six different switching circuits. I'he first terminates ata wire chiefs desk on key IKI which is arranged to apply ground to theidentification circuit and +48 volts to the T terminal of a first groupSelector. TB #2 of the second identification finder is connected with arelay IRI forming-part of the #l toll trunk and adapted to apply groundto the identification circuit and +46 volts to the T terminal of asecond4 group selector. 'I'he #3 test brush of the second identificationfinder is connected with the #2 toll trunk, the relay IR! oi which isarranged to apply ground to the identification circuit and +44 volts toa second GR. The #4 test brush of the second identificatiorrfinder isconnected with a relay IRS of an automatic ticketing arrangement adaptedto apply ground to the circuit and +42 ,volts to a second GR. The #5test brush is connected with relay IRA, forming part of a special lineservice which is/ adapted to apply ground to the circuit and voltsbattery to a third GR. The #6 brush of the second identification finderis connected with a special portable test Set which may be used byswitchmen to determine the number of a calling subscriber or trunk.- Thekey 1K2 in the special test set is adapted to apply ground to thecircuit. and +50 volts to any test terminal in the system.

Whenever any one of these keys IKI or IKZ or relays IRI-4 is operated,positive battery of 40 to 50 volts is applied to the test conductors ofthe connection that has been built up fromthe calling line through theexchange to the respective position. Through a positively polarizedrectifier S+ and a resistance R, this potential is applied to a commonstarting relay Gsr.

Assuming, for instance, that line 598 has been of which there is onelextended through a first line finder, a second line finder and a rstgroup selector, to the wire chiefs position, when the key IKI isactuated, +48 volts will be connected through the t wires of the firstgroup selector and the second line finder and then through S+3, R3 andGSR2 to ground Similarly, the test set may be connected to the test wireof a final selector and when key 1K2 is operated, +50 volts is appliedthrough this key and then through the penultimate, fourth, third, secondand first group selectors, the second line finder, S+I, RI and GSRI toground.

When GSRZ operates, it closes an energizing circuit from ground over itsarmature and front contact and the winding of power magnet PIS and theleft hand back contact and armature o relay TRS to grounded battery. Thepower magnet'PIS will control the movement of the brushes of the #5first identification finder to hunt for the t wire of the calling line,the terminals of this switch being multipled to the test wires of linesNos. 500-599 and thus to the test terminals of the first line findersserving this group of lines. When the calling line is found, a circuitis closed from ground over the winding of relay TRS, the left hand backcontact and armature of relay ARS, TBS, the terminal in the firstidentification finder and in the first line finder of line No. 599 andthe brush of the operated first line finder to the +48 volt batteryconnected thereto by the second LF from the wire chiefs key IKI. RelayTRS opens the circuit of magnet PIS and thus stops the firstidentification finder brushes. Over its right hand armature and frontContact, this relay closes an energizing circuit for the relay ARS whichlocks up to the ground applied by relay GSR2. Through its front contact,the relay ARS connects TBS of the first identification finder to itsassigned terminal in the banks of the second identification finders, inthe present case t2.

If the second toll trunk were selected by a line, e. g. #500, then uponthe operation of the toll identification relay IR2, GSR2 would beoperated from +44 volts over S(+) I and RI. Should this happen after thekey IKI is operated, then the circuit of the clutch magnet PIS will beopened by TRS when brush TBS reaches the first T terminal to whichbattery is applied. Since there is only one first identification finderper hundred lines, no double connection can take place. The toll call online 50D must wait for the identification of the line S99, which willhappen in two to four seconds. Should the key IKI and relay IRI of thefirst toll trunk be operated simultaneously, then both relays GSR! andGSRZ will be operated and will cause their associated first identicationfinders to hunt simultaneously.

' Each of. these will select the calling T terminal in its bank. The #lsecond identification finder will then pick up the first identificationfinder to which +48 volts was connected by key IKI and the #2 secondidentification finder will pick up the first identification finder towhich +48 volts was applied by relay IRI. This is so because as willpresently be described, each second identification finder can stop onlyon a predetermined potential applied to its terminals.

Fig. 2 shows a typical control circuit for the second identificationfinders. All these circuits are alike except that as indicated in Fig.1, they are connected tothe ground contacts of a difierent key IK or adifferent relay IR. The only difference between the various circuits isthat in each the battery marked -l-N volts has a different voltage. Thevoltage of this battery is given in the dotted square appearing adjacentto the second identification finder brushes in Fig. l and corresponds tothe voltage that is applied by the identification key or theidentification relay to the connection. This voltage is permanentlyconnected over a resistance R to the cathode of a three electrode vacuumtube VI and to the grid of a similar tube V2.

When the test brush TB of the second identification finder contacts withthe terminal to which the test brush of the first identification findervand the relay AR associated therewith has extended the calling testcircuit, then the test potential applied 'to this circuit, e. g. +48volts, Will be connected over the test brush of the secondidentification finder to the control grid of the first tube VI and thecathode of the second tube V2.

In the present case, upon the actuation of IKI a circuit is closed fromground through the'lower contact `of the key IKI, .the outer armatureand back contact of relay BR and the winding of relay AR of the secondI. F. to grounded battery. The relay AR becomes energized and closes anenergizing circuit from grounded battery over power magnet P of thesecond identification finder, the back contact and armature of relayGVR, the right hand armature and front contact of relay AR, the outerarmature and back contact of relay BR to ground at the key IKI.` Thepower magnet controls the movementof the brushes of the secondidentification finder #l until the test brush thereofAY encounters, asabove stated, the test terminal to which the key IKI had applied +48volts battery over the #5 first -I. F. When in the control circuit ofthe #l second identification finder the same potential is applied to thecathodes and the grids of both tubes, and only then, a gas valve GV willbe `-operated. 'While different potentials are` applied to Vl and V2 thecontrol electrode CE of GV will be kept below ionizing potential.However, when the same voltages are applied to the two tubes, then theywill not draw appreciable current and the full potential of the batteryHTB will cause GV to strike, whereupon relay GVR connected tothe anode Awill become energized. Thiswill open Vthe circuit of the magnet P andstop the second identification finder brushes on theselected terminals.The ground from key IKI is now extended by the armature of relay GVR tothe winding of relay BR which first locks up to the ground at the keyIKI and then breaks the circuit of relay AR. The gas valve GV isextinguished and the relay GVR becomes de-energized. The power magnet Pcannot again become energized. The relay BR remains locked up until theidentification key ory identification relay is released.

Fig. 3 illustrates other applications of the invention to telephoneselecting systems. Here again only the t wires are shown, the balance ofthe switching system being assumed to be of the type disclosed in mysaid co-pending application. In this arrangement, first and second linefinders, first group selectors, special service second group selectorsand toll third group selectors, are illustrated. The toll third groupselectors have access to a CLR toll board and a certain number ofdifferent groups of automatic ticketing positions and out-toll trunks.

A common starting relay GSR3 is connected in parallel to the t wires ofthe A links and a common starting relay GSR4 is connected in parallel tothe t wires of the toll third group selectors.

`ates the identication key,

, GSR3 and GSR4. As in Assuming, for instance, that a calling subscriberdials a number which will cause the automatic switches to operate toconnect his line with the CLR board, when the operator at this boardactushe will apply +46 volts to the t wire causing, as above stated, theenergizing of both relays GSR3 and GSR4. The rst identication lnder willthen be operated as explained in connection with Fig. l to pick up the twire whereupon the second identification finder, which is set for +46volts, will pick up the rst identification finder and cause the display-.ing of the number of the calling line on the number` indicator providedat the position of the CLR operator. i

GSRA plays no role in this connection since none of the auxiliary ndersis assumed to be set to operate on the application of +46 volts.

Should the CLR operator desire to introduce a repeater into theconnection, she will depress her repeater key causing the application of+54 volts to the t wire. This again will operate both relays the rstcase GSR3 will cause the first identification finder to pick up the twire but since none of the second identication nders is assumed to beset to operate on +54 volts, no second identification finder will selectthe first identification 'finden i, However, relay GSRd will cause someor all the auxiliary nders to hunt for the calling t wires in the sameman-y ner as GSR3 did for the rst I. F. The auxiliary finder markedRepeater is set for +54 volts (see Fig. 2) and its T brush will huntuntil it encounters the 1: wire leading to the toll third group selectorto which +54 volts was applied by the operator.

Obviously, each auxiliary nder has the required number of brushes andother means for controlling4 all the necessary switching operations. thetoll third group selector which operates when the auxiliary-finder picksup this group selector to'open the t wire towards the first line iinder.This will leave the t wire free from the repeater to the toll operatorfor such subsequent use as may be necessary for the control of therepeater, e. g., to adjust the gain of the amplier.

i Obviously, an allotter may be provided to assign the auxiliarycircuits, one at a time, to hunt for the call.'

Should the CLR operator wish to transfer the call to another operator,e. g.,at the A toll board, she may press her transfer key and apply +56volts to the t wire. This will cause an auxiliary nder to extend thecall to the A toll position.

The CLR operator may actuate the meter relay MR of the calling party asmany times as she wishes by depressing a metering key MMK which applies-48 volts to the t wire. Since the meter relay is connected with the twire over a negatively polarized rectier, only it and not the relaysGSR3 and GSR4 will be operated.

Assuming that the calling subscriber dials the number of a calledsubscriber associated with a distant exchange, and further assuming that+52 volts is applied to the t wire of the automatic out-trunk, theauxiliary nder marked automatic ticketer will connect with a toll thirdgroup selector. When this happens, it will operate the relay PRconnected with this group selector which The drawings merely show arelay PR in' opens the t wire towards the out-trunk. At the same \timethe automatic ticketer, by suitable means such as a relay, applies +42volts to the t wire towards the calling line. Not onlythe rst but alsothe second identification nder which is set to.operate on +42 volts,will now operate,V

after which the number of the calling party is transmitted to theautomatic ticketer in the same manner as described in connection withthe ,CLR position.

Assuming in the last case that a repeater was automatically introducedupon the Vselection of the out-trunk by applying +54 volts to the t wireafter having rst applied +52 volts, as. above described, a repeater willbe automatically connected with the circuit.

Fig. 4 illustrates how this invention is applied for controllingstraightforward trunking from a manual board. Each operator or group ofoperators has as many out-trunk jacks as are required for simultaneousout-trunk connections. In the drawings, six out-trunk groups, each grouphaving a common trunk finder bank multiple are shown. A specialpotential is assigned to each trunk. The band extends from +40 volts to+50 volts.y Each toll operator has a set of keys by means of whichcorresponding potentials may be applied to the t wire or sleeve of thecord. For instance, key Kl applies +50 volts, key K2, +48 volts, etc.,key K6, +40 volts.

When the operator depresses the proper key and inserts the plug of hercord circuit into a free out-trunk jack individual to her position or anadjacent position, then a common starting relay GSR5 is energized overresistance R, back contact and armature of relay ARS, the sleeve wire ofthe jack and plug, armature and back contact of relay CR, the positivelypolarized rectier S+,- and say, key K3 to +46 Volts. The relay GSR5closes an energizing circuit, from grounded battery over its armatureand front contact and the power magnets P of all the idle trunk findersin the group to ground to hunt for 4the calling line. As indicated inFig, 4, only the third group of trunk finders operates on +46 volts andtherefore only this one can respond when the particular cord is reachedto which +46 volts was connected, as has been explained in connectionwith Fig. 2. When this happens, relay ARS is energized, opens thecircuit of relay GSR5, whereupon all the unsuccessfully hunting trunkfinders will stop. ARE will apply negative battery over resistance R andits right hand front contact and armature to the sleeve of the jack andplug, whereby relay CR, which is grounded over a negatively polarizedrectier S becomes energized and disconnects the keyset which may now beused with another cord circuit.

Obviously, the invention is applicabile to many other selective ortrunking schemes.

Whatl is claimed is:

1. In combination, a rst and a second switching device, a source ofpotentials, means for applying pairs of different potentials to saiddevices, eachpar of potentials representing a different switchingoperation, means operative upon the application of any pair ofpotentials for acof selectively operable devices, a source ofpotentials, means for applying a plurality of?, pairs oi' I operativeupon the application of any potential for actuating the ilrst group ofdevices to perform the rst step of the selecting operation designated bythe potential applied thereto, and means for operating the second groupdevice to which the other potential of the pair has been applied toperform the second step of the selecting operation.

3. In combination, a first and a second group of selectively operabledevices, a plurality of lines, a source of potentials, means forapplying a plurality oi' diierent pairs of identical potentials, one tosaid lines and the other to the second group of devices, means operativethereupon for actuating the first groupof devices to select the line towhich the potential has been applied, and means for operating the secondgroup device to which the same potential has been applied as to the lineto select the operated iirst device.

4. In combination, a ilrst and a second group of selectively operabledevices, a plurality of lines, a source of potentials, means forapplying a plurality of dierent potentials to said lines and secondgroup of devices, means operative thereupon for actuating the ilrstgroup of devices to connect with the line to which the potential hasbeen applied, and means for operating the second group device to whichthe same potential has been applied as to the line to connect with saidline over the operated iirst device. o

o. In combination, a iirst and a second group of selectively operabledevices, each having a bank of terminals and a cooperating set ofbrushes, a plurality of lines connected in multiple to the terminalbanks of the ilrst devices, a source of potentials, means for applying aplurality of different potentials to said of the second group ofdevices, means operative thereupon for actuating the first group ofdevices to connect with the terminal of the line to which the'potentialhas been applied, and means for operating the second group device towhich the same potential has been applied as to the line to connect withsaid line over the brushes of the operated first device.

6. In combination, a first and a second group oiiselectively operabledevices, a, plurality of lines, a source of D. C. potentials, means forapplying potentials diiering in voltage between predetermined lower andupper limits to said lines and second group of devices, means operativethereupon for actuating the rst group of devices to connect with theline to which 'a potential has been applied. and means for operating thesecond group device to which potential of the same volt age has beenapplied as to the line to connect with said line over the operated firstdevice.

7. In combination, a plurality of groups of rst selectively operabledevices, a plurality of second selectively operable devices, a source ofpotentials, means for applying different potentials from lsaid source toone of the groups of first devices and to the second devices, eachpotential designatlng a different selecting operation, means operableupon the application of any potential to the iirst group for operating arst device of said group to perform the operation designated by thelines and to the brushes' f lng group to engage the tipled to the linesof the corresponding group and a set of cooperating brushes, a pluralityof second selectively operable devices, each having a set of brushes anda cooperating bank of terminals to which the brushes of all the theiirst devices are multipled, a source of potentials, means for applyingdifferent potentials from said source to said lines and to the brushesof the second devices, means operable upon the application of anypotential to a' line of a group for operating the iirst devices of thecorresponding group to operate the brushes for engaging the terminals ofsaid line, and means operative thereupon for actuating the brushes ofthe second device to which the same potential has been applied as to theline to engage the terminals to which the brushes of the operated lrstdevice are multipled.

9. In combination, a plurality of groups of lines, a, plurality ofgroups of rst selectively operable devices,`one group for each group oflines,

each device having a, bank of terminals multipled to the lines of thecorresponding group and a' set of cooperating brushes, a plurality ofsecond selectively operable devices, each having a .set of brushes and acooperating bank of terminals to which the brushes of all the rstdevices are multipled, a source of D. C. potentials, means for applyinga potential of diierent voltages from said source to said lines and acertain voltage to the brushes of each second device, means operableupon the application of any'voltage to a line of a group for operatingthe brushes of the rst devices of the corresponding group to engage theterminals of said line, and means operative thereupon for actuating thebrushes of the second device to which the same voltage has been appliedas to the line to engage the terminals to' operated first device whichthe brushes of the are multipled.

l0. In combination, a, plurality of` groups of lines, a plurality ofgroups of iirst selectively operable devices, one group for each groupof lines, each device having a bank of terminals multipled to the linesof the corresponding group and a set of cooperating brushes, a pluralityof second selectively operable devices, each having a set of brushes anda cooperating bank of terminals to which the brushes of all the firstdevices are multipled, a source of potentials, means for applyingdiiferent potentials from said source to said lines and to the brushesof the second devices, means operable upon the application of anypotential to a line of a group for operating the brushes of the rstdevices of the correspond- Aterminals of said line, and means operativethereupon for actuating the brushes of the second device to which thesame potential has been applied as to the line to engage the terminalsto which the brushes of the operated rst device are multipled.

GERALD DEAKIN.

-, CERTIFICATE oF CQRRECTION.

Patent No. 2,576,5Li6. may 22, 1915.

GERALD DEAKIN.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page l,second column, line 21, before the word "brush" insert --one illustratedin Fig. 2, is associated with the t-f; and that the said Letters Patentshould be read with this correction therein that the same may conform tothe record of the case in the Patent Office.

signed and sealed this 6th dey of November, A. D. 19LL5.

Leslie Frazer (Seal) First Assistant Commissioner of Patents.

